A rear-end pre-crash safety system which performs a rear-end pre-crash safety control which is a control to detect an approaching vehicle approaching an own vehicle from rear and to enhance safety against a collision of the approaching vehicle with the own vehicle has conventionally been known. The rear-end pre-crash safety control is a control to prevent the approaching vehicle from rear from colliding with the own vehicle, or a control to secure a safe posture for a driver in advance in preparation for a case where the approaching vehicle collides with the own vehicle.
For example, following controls, that is, a control to issue a warning to a driver of the approaching vehicle by blinking hazard lamps (Japanese Patent Application Laid-Open (kokai) No. 2010-201951), a control to adjust a front-rear position of a headrest, and a control to retract a seatbelt (eliminate a looseness of the seatbelt) have been known.